Slide fastener and method of making same

ABSTRACT

A coupling element of the meandering-coil type, with a row of coupling heads formed on bight portions of a series of loops of a monofilament lying substantially in planes perpendicular to that row, is tied to a warp-knitted fabric by knitting stitches interlinking either or both shanks of each loop with a plurality of wales paralleling the row of coupling heads. The transverse courses defined by the warp chains have a spacing equal to the loop spacing, or to an aliquot fraction thereof, with the boundin loop shanks passing through the meshes between successive courses. The warp thread or threads nearest the coupling heads may be of elastic material, in contradistinction to those remote therefrom which should be substantially inelastic.

United States Patent Fr'tihlich SLIDE FASTENER AND METHOD OF MAKING SAME [75] Inventor: Alfons Friihlich, Essen, Germany [73] Assignee: Opti-Holding AG, Glarus,

Switzerland [22] Filed: Apr. 9, 1973 [2]] Appl. No.: 349,005

[30] Foreign Application Priority Data Apr. 7, 1972 Germany 2216829 [52] US. Cl 66/193, 66/86 R, 24/2051 [51] Int. Cl. D04b 23/08, D04b 23/10 [58] Field of Search 66/86, 190, 192, 193, 195; 24/2051 [56] References Cited UNITED STATES PATENTS 3,651,666 3/1972 Austin et a1 6 6/86 R 3,657,904 4/1972 Austin et al 66/86 R 3,750,425

8/1973 Austin et al 68/86 R Primary E.\'aminerR0nald Feldbaum Attorney, Agent, or Firm-Karl F. Ross; Herbert Dubno [57] ABSTRACT A coupling element of the meandering-coil type. with a row of coupling heads formed on bight portions of a series of loops of a monofilament lying substantially in planes perpendicular to that row, is tied to a warpknitted fabric by knitting stitches interlinking either or both shanks of each loop with a plurality of wales paralleling the row of coupling heads. The transverse courses defined by the warp chains have a spacing equal to the loop spacing, or to an aliquot fraction thereof, with the bound-in loop shanks passing through the meshes between successive courses. The warp thread or threads nearest the coupling heads may be of elastic material, in-contradistinction to those remote therefrom which should be substantially inelastic.

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M :L h! HUI T VJ!) 61F I; W M (w v 4 L JI @174 A m aw w m (a 03/ SLIDE FASTENER AND METHOD OF MAKING SAME FIELD OF THE INVENTION My present invention relates to a coupling element adapted to be used, in its entirety or in part, as a slidefastener half co-operating with a similar element under the control of a slider.

BACKGROUND OF THE INVENTION In commonly owned US. Pat. applications Ser. Nos. 82,323 and 82,326 filed by me jointly with Marie-Luise Cappel and Ernst Stiibiger on Oct. 19, 1970, now US. Pat. Nos. 3,767,541 and 3,7 l4,683, there has been disclosed a slide fastener whose coupling elements are stitched onto warp-knit stringer tapes.

Attempts have already been made to tie such coupling elements directly into the supporting stringer tapes during the knitting of the tapes themselves. The resulting slide-fastener halves, however, were not satisfactory since their anchoring to the fabric structure did not insure the necessary uniformity of the spacing of their coupling heads and did not afford sufficient protection against deformation of the coupling element either in the plane of the fastener or in a direction perpendicular thereto.

OBJECTS OF THE INVENTION It is, therefore, the general object of my present invention to provide an improved slide-fastener half organically bound into the structure of a knitted fabric, which could be a stringer tape or part of a garment or the like to be equipped with the fastener.

A related object is to provide an expeditious method of making such a combination of a coupling element and an associated fabric structure.

SUMMARY OF THE INVENTION I have found, in accordance with this invention, that a reliable connection between a coupling element and an associated fabric structure of the warp-knit type can be realized if the coupling element is so shaped, in a manner known per se, as to form a multiplicity of generally planar transverse loops each with two substantially parallel shanks interconnected by a bight portion which carries a coupling formation (generally a pair of oppositely facing coupling heads), the planes of the loops being perpendicular to the wales of the fabric structure. In accordance with conventional knitting technique, these wales are formed by chains of warp threads at least some of which are tied around either or both shanks of each loop. The spacing of the loops should equal a whole number of times the spacing of the transverse courses defined by the warp chains, i.e., the stitch length of the fabric; thus, each bound-in loop shank comes to lie between successive loops. A coupling element of the character described can be a conventional meandering monofilament of thermoplastic material, such as a polyamide (nylon).

The width of the fabric structure may equal that of the coupling element, in which case the bound-in shanks are all that is needed to link'the several wales to one another so that the use of a weft is not necessary. However, the fabric may also be wider than the coupling element and in that event should include weft links which may partly extend into the region between the coupling loops.

In some instances it will be desirable to omit the coupling heads on every other loop and to let these latter loops terminate short of the coupling element defined by its coupling heads. The headless loops, wh'ose foreshortening provides spaces for the penetration of the coupling loops of the complementary fastener half, then serve merely as mechanical reinforcements for the actual coupling loops since the loop spacing may be quite close in that case.

If both shanks of each loop are to be tied into the fabric by its warp chains, these chains may form common meshes around the two shanks which is easily done if the loops are narrow. However,.it is also possible to let the shanks of each loop be engaged by separate warp chains which may or may not be interlinked. in pairs,

and which thus form part of separate tape portions. In

a particularly advantageous method of manufacturing slide-fastener halves of the latter description, I start with a flat undulating monofilament having the coupling heads disposed along a centerline bisecting its un-' dulations; two groups of warp threads then engage respective half-sections of these undulations whereupon the monofilament is bent about its centerline so as to place the two half-sections in substantially parallel planes where they form the shanks of the loops.

According to a further feature of my invention, the necessary yieldability of the coupling heads combined with structural rigidity of the overall fastener is enhanced by making one or more warp threads proximal to the coupling heads of relatively elastic material and making the remaining loop-engaging warp threads, remote from the coupling heads, of relatively inelastic material.

BRIEF DESCRIPTION OF THE DRAWING The above and other features of my invention will now be described in detail with reference to the accompanying drawing in which:

FIG. 1 is a plan view of a representative portion of a slide-fastener half embodying my invention;

FIG. 2 is a cross-sectional view taken on the line [I ll of FIG. 1;

FIGS. 3 and 4 are views similar to FIG. 2, showing different modifications;

FIG. 5 is another cross-sectional view illustrating a complete slide fastener together with an associated slider;

FIG. 5A is a fragmentary plan view of a fastener half shown in FIG. 5;

FIG. 6 is a plan view similar to FIG. 1, showing another embodiment;

FIG. 7 is a cross-sectional view similar to FIG. 5, taken on the line VII VII of FIG. 6; and

FIG. 8 is a plan view of a precursor of a slide-fastener half of the type illustrated in FIGS. 6 and 7, illustrating the method of its formation.

SPECIFIC DESCRIPTION Each of the several slide-fastener halves shown in the various views of the drawing comprises, basically, a warp-knit fabric 1 and an elongate coupling element 2 organically bound to each other, i.e., with all the warp threads of the fabric in a zone 4 thereof tied directly to the coupling element. This element 2 is a meandering monofilament with a multiplicity of loops lying in planes P transverse to a line 7 which is the longitudinal axis of symmetry of a complete slide fastener (see, for

example, FIG. 6) and which lies close to a longitudinal edge of the fabric confronting the other slide-fastener half. Each loop includes a lower shank 5 and an upper shank 6 as well as a bight portion 8, all lying substantially in the transverse plane P, as well as a pair of coupling heads 9 on bight portion 8. The loops are integrally interconnected by links 10 extending generally parallel to line 7.

The fabric 1 of FIGS. 1 3 has a width greater than that of coupling element 2 so that a section 3 thereof. adjacent zone 4, lies rearwardly of the links 10. Section 3 includes weft threads laid-in among warp chains forming wales 11 which are parallel to line 7, these weft threads following a 3-3/0-0 pattern as explained in the two commonly owned applications and patents identified above. It will be understood that the lay of these weft threads is not critical and might range over a smaller or large number of wales. Similarly, the fabric zone 4 occupied by the coupling element 2 may encompass different numbers of wales, eg between two and 10. These wales are chained in a simple tricot stitch or fringe pattern 0-l/ 1-0 though other patterns could also be used. They could be supplemented, for example, by ancillary threads laid in a twill pattern 2-0/0-2 or in a canvas pattern l-0/23. Some of the weft threads 15 extend into the zone 4 for the purpose of providing a denser fabric structure in area 3; their presence in zone 4 is otherwise not essential.

The spacing of planes P, which contain the coupling loops of element 2, corresponds to the stitch length 14 between successive courses 12 which coincide with the vertices of the undulations of weft threads 15. As explained above, the loop spacing could also be a whole multiple of stitch length 14.

In the assembly of FIGS. 1 and 2, the warp threads of zone 4 are cast around both shanks 5 and 6 of each loop coupling which is thereby fully bound into the fabric. These shanks may be provided with projections or other surface formations, as shown at 13 in FIG. 4, to hold the warp threads in position on the shanks 5 and 6. In many instances, especially with straight shanks, a simple roughening of the filament surface will suffice to accomplish this aim.

The fastener half of FIG. 3 is produced with a reduced stroke of the knitting needles so that the warp threads 11 of zone 4 pass only around the lower shank 5 of each loop.

FIG. 4 illustrates the possibility of forming separate but interlinked meshes about the upper and lower shanks of each loop. This Figure further illustrates that the lower shanks 5' of the loops of a modified coupling element 21 may be extended into the fabric zone 3 offset from the upper shanks 6, thereby eliminating the need for weft linkages in that zone.

In FIGS. 5 and 5A I have shown two interengaging slide-fastener halves whose coupling elements 2 form alternating shorter and longer loops with shanks 5a, 6a and 5b, 6b, respectively. The associated fabrics, whose width in this case is limited to that of the coupling elements, have sections 1' and 1" respectively engaging the lower shanks 5a, 5b and the upper shanks 6a, 6b. These fabrics are additionally fastened by stitching 18 to sheets 16 which may be parts of garments or other articles joined to each other by the fastener. The latter includes a slider 19 of the type described and claimed in my copending application Ser. No. 348,110 filed Apr. 5, I973; this slider has a pair of coplanar wings 20 in camming engagement with bight portions 8a of the shorter loops which closely adjoin the longer loops carrying the coupling heads 9 on their bight portions 8b.

The projecting parts of the longer loops are engaged by warp threads forming forwardly positioned wales 11 which, as indicated in FIG. 5A, may be relatively elastic compared with the inelastic warp threads forming rearwardly positioned wales 11 to which all the loops of element 2 are anchored. The spacing of these loops, and therefore of the intervening courses 12, is substantially closer than in FIG. 1 since the foreshortening of the shanks 5a and 6a relatively to the shanks 5b and 6b affords sufficient space for the penetration of the opposing coupling heads. The stitching 18 is disposed beyond the area of penetration and may pass through filler cords 17 as illustrated in FIGS. 6 and 7; the latter Figures show an arrangement differing from that of FIGS. 5 and 5A only in the fact that all loops have shanks 5, 6 of equal length and bight portions 8 carrying coupling heads 9.

FIG. 8 shows a precursor ofone of the fastener halves of FIGS. 6 and 7, with the monofilament 2 undulating in one planev and having the coupling heads 9 disposed on a centerline C bisecting its undulations. The sections of these undulations on opposite sides ofthat centerline are engaged by wales 11, 11 of separate fabric strips 1 which come to lie in parallel planes, one above the other, when the 'monofilament is bent into U-shape about centerline C into the form shown in FIGS. 6 and 7. Aside from this bending operation, which requires a heat-softening of the thermoplastic monofilament, I prefer to preshape these monofilaments so that they are already looped and provided with coupling heads before being interknitted with the associated fabric structure.

Naturally, the combination of elastic and inelastic threads shown at 11 and 11 in FIGS. 5A and 8 may be used in any of the described embodiments.

In the fabric structures of FIGS. 4 8, in which the weft threads 15 of FIGS. 1 3 are omitted, the waleforming warp chains 11, 11' are held together only by the monofilament 2 which is therefore essential to the coherence of the structure.

1. A slide-fastener half comprising:

an elongate monofilam entary coupling element forming a multiplicity of generally planar transverse loops each with two substantially parallel shanks interconnected by a bight portion, the bight portions of at least some of said loops bearing coupling heads engageable with complementary coupling heads on an adjoining slide-fastener half; and

a warp-knit fabric structure with chains of warp threads forming a plurality of parallel wales perpendicular to said loops, the shanks of each loop extending across several of said wales having chain stitches tied around at least one shank of each loop.

2. A slide-fastener half as defined in claim 1 wherein, the spacing of said loops equals the length of said chain stitches.

3. A slide-fastener half as defined in claim 1 wherein the chain stitches of said several of said wales form common meshes around both shanks of each loop.

4. A-slide-fastener half as defined in claim 1 wherein said several of said wales comprise pairs of warp chains respectively engaging the shanks of each loop.

5. A slide-fastener half as defined in claim 4 wherein said pairs of warp chains are interlinked between said shanks.

6. A slide-fastener half as defined in claim 1 wherein said monofilament is of meandering configuration.

7. A slide-fastener half as defined'in claim 6 wherein the warp thread of at least one chain proximal to said coupling heads is elastic, the warp thread of at least one chain remote from said coupling heads being relatively inelastic.

8. A slide-fastener half as defined in claim 6 wherein said fabric structure has a width greater than atleast the other shank of each loop.

9. A slide-fastener half as defined in claim 8 wherein said one shank is longer than said other shank.

10. A slide-fastener half as defined in claim 6 wherein said monofilament is provided with surface formations holding said warp threads in position thereon.

11. A slide-fastener half as defined in claim 6 wherein only the bight portions of alternate loops are provided with said coupling heads, the intervening loops terminating short of an edge of said coupling element defined by said coupling heads.

12. A slide-fastener as defined in claim 1 wherein said fabric structure includes laid-in weft threads interlinking said warp threads.

13. A method of making a slide-fastener half, comprising the steps of:

forming an elongate monofilamentary coupling element with a multiplicity of generally planar loops having each two substantially parallel shanks interconnected by a bight portion transverse thereto, the bight portions of at least some of said loops bearing coupling heads engageable with complementary coupling heads on an adjoining slidefastener half; and

knitting chains of warp threads to form a fabric structure with a plurality of parallel wales perpendicular to said loops, with engagement of at least one shank of each loop by chain stitches of several of said parallel wales for tying said coupling element into said fabric structure.

14. A method as defined in claim 13 wherein said half-sections of said undulations, followed by a bending Q of said monofilament about said centerline with placement of said half-sections in substantially parallel planes to form said shanks. 

1. A slide-fastener half comprising: an elongate monofilamentary coupling element forming a multiplicity of generally planar transverse loops each with two substantially parallel shanks interconnected by a bight portion, the bight portions of at least some of said loops bearing coupling heads engageable with complementary coupling heads on an adjoining slide-fastener half; and a warp-knit fabric structure with chains of warp threads forming a plurality of parallel wales perpendicular to said loops, the shanks of each loop extending across several of said wales having chain stitches tied around at least one shank of each loop.
 2. A slide-fastener half as defined in claim 1 wherein, the spacing of said loops equals the length of said chain stitches.
 3. A slide-fastener half as defined in claim 1 wherein the chain stitches of said several of said wales form common meshes around both shanks of each loop.
 4. A slide-fastener half as defined in claim 1 wherein said several of said wales comprise pairs of warp chains respectively engaging the shanks of each loop.
 5. A slide-fastener half as defined in claim 4 wherein said pairs of warp chains are interlinked between said shanks.
 6. A slide-fastener half as defined in claim 1 wherein said monofilament is of meandering configuration.
 7. A slide-fastener half as defined in claim 6 wherein the warp thread of at least one chain proximal to said coupling heads is elastic, the warp thread of at least one chain remote from said coupling heads being relatively inelastic.
 8. A slide-fastener half as defined in claim 6 wherein said fabric structure has a width greater than at least the other shank of each loop.
 9. A slide-fastener half as defined in claim 8 wherein said one shank is longer than said other shank.
 10. A slide-fastener half as defined in claim 6 wherein said monofilament is provided with surface formations holding said warp threads in position thereon.
 11. A slide-fastener half as defined in claim 6 wherein only the bight portions of alternate loops are provided with said coupling heads, the intervening loops terminating short of an edge of said coupling element defined by said coupling heads.
 12. A slide-fastener as defined in claim 1 wherein said fabric structure includes laid-in weft threads interlinking said warp threads.
 13. A method of making a slide-fastener half, comprising the steps of: forming an elongate monofilamentary coupling elemenT with a multiplicity of generally planar loops having each two substantially parallel shanks interconnected by a bight portion transverse thereto, the bight portions of at least some of said loops bearing coupling heads engageable with complementary coupling heads on an adjoining slide-fastener half; and knitting chains of warp threads to form a fabric structure with a plurality of parallel wales perpendicular to said loops, with engagement of at least one shank of each loop by chain stitches of several of said parallel wales for tying said coupling element into said fabric structure.
 14. A method as defined in claim 13 wherein said monofilament is initially formed into a series of flat undulations having said coupling heads diposed along a centerline bisecting said undulations, with the warp chains of said several of said wales forming two groups on opposite sides of said centerline engaging respective half-sections of said undulations, followed by a bending of said monofilament about said centerline with placement of said half-sections in substantially parallel planes to form said shanks. 